About the left/right sticks QTE (when there are a lot of them), just do some fast circles with both sticks, and you won't have to worry about pushing the good direction.

When you have a QTE with Y or B (boss counters, smash both buttons, it works 90% of the time).

During the shoot'em up parts, hold on X to shoot and smash Y the whole at a low pace when you have to do some missiles counters, that's way you don't have to worry about QTE timing (I think you can even just hold on Y, that's what I was doing at the beginning and it was working, but dunno if it's work everywhere).